Mossbauer effect experiments will be done on several iron transport compounds such as the mycobactins, enterobactin and some synthetic analogues to study the electronic structure (the chemical state) of the iron in each case. The electric and magnetic hyperfine interactions which reflect the electronic structure about the iron ion, give each spectrum a characteristic profile, even in powder samples. The data can then be analyzed in terms of some spin Hamiltonian parameters which describe the electronic structure of the iron ion and its environment. Experiments with Fe57 in concanovalin A-a saccharide binding protein from Jack bean - will be done to study the influence of Ca ions and saccharide on the chemical state of the Fe atom. Since both Ca ions and Fe ions must be present for saccharide binding to occur, there is a probable interaction. Other experiments will involve electron spin resonance (ESR) of the iron transport compounds and computer synthesis of the ESR spectrum to analyze the effects of the extreme rhombic environment. Work will also be done to study the chemical states of the iorn as it passes through a membrane such as the cell wall of a reticulocytes.